This book is addressed primarily at government project evaluators and is divided into four parts. Part I reviews the reasons for the need for project evaluation, discusses in detail the various objectives that governments typically consider in their national plans, and what role public investment is likely to play in the realization of such objectives. Part II contains a detailed discussion of the shadow prices used in Part I. Part III discusses the meaning and significance of national parameters, social rates of discounting, social values of investment, the shadow prices of unskilled labour and foreign exchange, and the role of national planning in project formulation and evaluation. Part IV presents four case studies.